Minimally Invasive Chevron Akin: Locking the Metatarsal-Cuneiform Joint

Abstract

Category: Bunion Introduction/Purpose: Minimally Invasive Chevron Akin (MICA) can be used to treat hallux valgus (HV) associated with a hypermobility of the first metatarsal-cuneiform joint (1MTCJ). The aim of this study was to perform a radiographic analysis of the MICA, focused on evaluating the 1MTCJ. Methods: Forty patients (50 feet) with moderate to severe HV underwent a MICA procedure. Radiographic analysis included hallux valgus angle (HVA), intermetatarsal angles between the first and second rays (IMA), the intermetatarsal angle between the proximal fragment of the osteotomy and the second ray (IAPF) and the distance between a point 3 cm distal from the base of the second metatarsal and a point located at the same height for the first metatarsal base (Dist 1-2). The IAPF was compared with the preoperative IMA and the other parameters were compared pre and post-operatively. The radiographic complications were also recorded Results: The majority of patients were female (92%). The mean age was 50.4 years (SD =16.1) and the mean follow-up was 16.1 months (SD = 3.5). The average HVA improved from 32.5 to 7.3 degrees and the average IMA from 14.2 to 4.2 degrees. The IAPF and Dist1-2 values showed an increase of 4.8 and 3.2mm respectively. There were no radiographic complications Conclusion: Minimally Invasive Chevron Akin: Locking the Metatarsal-Cuneiform Joint.

Defining the Cortical Purchase Zone in New Minimally Invasive Bunion Surgery. A Retrospective Study of 638 Cases.

“…It has been documented that MIBS "locks-up" the first tarsometatarsal joint by adducting the proximal metatarsal segment, and this maneuver (we have found) allows for increased cortical runway. 25 The effect of tarsometatarsal mobility on CPZ was not studied as a part of this investigation and an area for future research that might help surgeons plan and perform MIBS.…”

Five-Year Follow-up of Third-Generation Percutaneous Chevron and Akin Osteotomies (PECA) for Hallux Valgus

“…A recent study has shown that the mean "proximal M1 fragment IMA" increases by 4 degrees (from the preoperative 1-2 IMA) following MIS HV surgery. 38 Further studies investigating the impact of medialization of the first TMTJ and proximal medial fragment are needed to understand if this has any role or impact on recurrence of hallux valgus deformity or degeneration of this joint. The percutaneous technique also allows rotational correction of the first metatarsal, which is increasingly recognized as an important factor leading to recurrence.…”