SLR - July 2018 - David Cain

Can the Syndesmosis Procedure Prevent Metatarsus Primus Varus and Hallux Valgus Deformity Recurrence? A Five-Year Prospective Study

Reference: Wu, Daniel Yiang, MD, Lam, Eddy Kwok Fai, PhD Can the Syndesmosis Procedure Prevent Metatarsus Primus Varus and Hallux Valgus Deformity Recurrence? A Five-Year Prospective Study. Journal of Foot and Ankle Surgery. April 2018, Volume 57, Issue 2, pp. 316–324.

Scientific Literature Review

Reviewed By: David Cain, DPM
Residency Program: Columbia St. Mary’s Hospital, Milwaukee, WI

Podiatric Relevance: The following presents a unique Hallux Valgus (HV) correction technique with excellent results. This procedure could be extremely useful, especially with pediatric patients suffering from HV deformities. This would prevent disruption of growth plates and allow for arthrodesis procedures to be performed in the future if needed.

Methods: Thirty-two consecutive patients (60 feet) underwent the syndesmosis procedure for HV deformity correction without any deformity limitations or selection criteria, other than the radiologic criteria of an IMA >9 degrees or a metatarsophalangeal angle >20 degrees and the clinical criterion of unsatisfactory conservative management results. Of 32 patients, 29 (90.6 percent), with a total of 55 procedures [26 (89.7 percent) bilateral and three (10.3 percent) unilateral], completed the five-year prospective follow-up study. Mean follow-up was 63.2 (range 60 to 83) months. The entire study population was female, and none had undergone previous foot surgery or had suffered trauma. Mean age at surgery was 39. All underwent clinical and radiologic preoperative 10-day, three-month, six-month, one-year, two-year and five-year postop visits. Radiographic exams were conducted using an identical protocol. 

A one-inch incision was made along the distal dorsal medial border of the second metatarsal. The lateral collateral and metatarsosesamoid ligaments were released. The adductor hallucis tendon was not released, and the fibular sesamoid was not resected. The distal one third of the first and second metatarsals were then fish-scaled with an osteotome. Three 2 mm drill holes were made in the distal half of the first metatarsal shaft about 5 mm apart in the dorsoplantar direction. Double strand #1 polydioxanone dissolvable sutures were then passed through the drill holes and around the second metatarsal.

Weightbearing was permitted as tolerated immediately after surgery in a custom-made removable foot cast-brace for three months. Patients were instructed on MTPJ strengthening, active/passive ROM from postop day one for six weeks. Patients returned to unprotected walking in regular shoes after three months. Unrestricted activities and shoes were allowed six months postoperatively.

Results: Mean IMA changed from 14.5 to 4.3 degrees, and mean MPA changed from 32.0 to 15.2 degrees. At six months postop, the angles had increased, IMA to 7.0 and MPA to 18.2 degrees. Mean angles at six months, one year, two years and five years postop were not statistically different.

Conclusions: Soft-tissue procedures using nonosteotomy and nonarthrodesis methods have generally been regarded as less effective, especially for moderate and severe deformity correction and recurrence prevention. However, the syndesmosis technique has been shown to be effective reducing the IMA to an average of 4.3 degrees using intermetatarsal cerclage sutures alone.

Previous concerns of poor MPV correction without osteotomies might not be valid and should be reexamined. The current study provides evidence that the syndesmosis-like soft tissue bonding between the first and second metatarsals can stabilize the first metatarsal and prevent MPV deformity recurrence for five years. The syndesmosis procedure produced satisfactory results and can be considered an effective and safe alternative to the current osteotomy and arthrodesis procedures for HV deformity correction. 

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