AOFAS 2022 Quebec City: Poster: Results of DMMO limited to 2nd and 3rd rays about 118 cases

Introduction: The objective of this study was to evaluate the clinical and radiological results of DMMO limited to the second and third rays in patients suffering from metatarsalgia with lesion of the plantar plate of the second ray associated with a hallux valgus. Our hypothesis was that this gesture allowed an improvement of the clinical and paraclinical symptoms.

 

Material and method: For this retrospective, single-center, single-operator study, 112 patients (mean age 65.52 years, 91% women, 127 feet) operated between June 2015 and October 2020 were included based on the following criteria: metatarsalgia complicated by lesion of the plantar plate with hallux valgus. Secondary metatarsalgia, congenital malformation, pes cavus, Freiberg’s disease, gastrocnemius retraction were excluded

 

The surgery began with DMMOs of the 2nd and 3rd metatarsals, then a minimally invasive chevron osteotomy adjusted the length of the 1st metatarsal in relation to the lateral rays. The position of the toes was guided by a bandage for 2 weeks relayed by a molded orthoplasty for 4 weeks. Support was complete with a rigid flat shoe.

At a mean follow-up of 3 years (14-80 months), the AOFAS functional score and radiographic measurements (Maestro criteria, bone consolidation) were evaluated.

 

Results:

The clinical improvement was significant with an AOFAS score going from 44.9 to 91.8 (p>0.05)

We observed 8.7% of complications: 4 transfer metatarsalgia on the 4th or 5th metatarsal, 1 asymptomatic callus under M4, 1 asymptomatic nonunion of M2, 5 spontaneously resolving delayed consolidation, 1 algodystrophy.

The radiographic improvement was significant on our morphotypes which were disharmonious in 92% with M45 hypoplasia in 76% and long M23 in 16%.

Indeed, the DMMO limited to the 2nd and 3rd metatarsal allowed a significant reduction in the difference in length between the 3rd and 4th metatarsal (p>0.05)

Our 4 cases of transfer metatarsalgia under M4 or under M5 were not explained radiologically by relative length anomaly.

 

Conclusion: Performing DMMO limited to the 2nd and 3rd metatarsals appears to be a reliable solution in the management of metatarsalgia by lesion of the plantar plate associated with hallux valgus, the risk of transfer metatarsalgia was not increased compared to the data of literature.