SLR - July 2017 - Emily Sanphy

Anatomical Reconstruction of the Fourth Brachymetatarsia with One-Stage Iliac Bone and Cartilage Cap Grafting

Reference: Woo SH, Bang CY, Ahn HC, Kim SJ, Choi JY. Anatomical Reconstruction of the Fourth Brachymetatarsia with One-Stage Iliac Bone and Cartilage Cap Grafting. JPRAS. 2017 Feb; 70:666–72.

Scientific Literature Review

Reviewed By: Emily Sanphy, DPM
Residency Program: MetroWest Medical Center, Framingham, MA

Podiatric Relevance: Congenital brachymetatarsia results in an abnormally short toe due to an interruption in the growth of a metatarsal. Distraction osteogenesis, while a popular surgical procedure for brachymetatarsia, often requires multiple trips to the operating room and necessitates strict patient compliance. Because the cause of brachymetatarsia is thought to be from premature closing of the distal epiphyseal growth plate, this study evaluated the use of an autogenous iliac bone graft at the epiphysis with repositioning of the MTPJ articular cartilage cap for a single-stage surgical treatment of fourth metatarsal brachymetatarsia.

Methods:
This is a retrospective review of 56 feet in 41 patients with congenital brachymetatarsia of the fourth who were treated with a single-staged autogenous iliac bone grafting over an eight-year period. The primary treatment goal for all patients was cosmetic improvement. The procedure involved a Z-plasty skin incision over the fourth MTPJ with a Z-lengthening of the extensor digitorum longus tendon and dorsal MTPJ capsule excision. Autogenous bone graft was then harvested from the contralateral limb and inserted into the new cartilaginous cap using a K-wire. The K-wire was then driven into the metatarsal base to allow graft interposition. The graft site was fixated with two crossed K-wires. Postoperative course included heel-touch partial weightbearing ambulation in short leg splints with crutch shoes. K-wires were removed at eight weeks with confirmed radiological union. Radiological evaluation included pre- and postoperative metatarsal length gains and percentages. If MRI was used, the viability of the cartilage cap was assessed. Functional evaluation was performed via AOFAS scores. Cosmetic evaluation was based on overall foot configuration, scarring, donor site morbidity and symmetry of the bilateral feet.

Results:
The mean follow-up period was 43.6 months. The mean fixation period was 58.5 days, and the mean length gain was 20.9 mm or a 39 percent increase in preoperative length. Eighteen patients opted into having an MRI, and 15 showed minimal to no MTPJ irregularity. There was one case of nonunion, which was asymptomatic and did not require revision. Mean AOFAS score was 82.0, and all patients reported that they would undergo the same procedure if necessary.

Conclusions:
The authors propose a successful option for single-staged surgical correction of brachymetatarsia using autogenous bone grafting to the epiphysis of the fourth metatarsal. There seemed to be fewer complications and increased length gain as compared to a study by Lee et al., which reviewed a single-staged graft into the metatarsal shaft. The authors reported limitations in assessing cartilaginous cap viability due to the low number of MRIs. After reviewing this article, it was unclear if this was a single-surgeon or multiple-surgeon procedure. Exclusion and inclusion criteria were not clearly defined. While outcomes appeared to be good overall, it is difficult to assess functionality of the procedure when the primary goal was cosmetic. With the need for a second specialist to perform the bone graft harvesting in many states, the use of allogenic iliac bone graft at the epiphysis should be investigated. 

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