SLR - March 2011 - Kristin J. Brown
Reference: Lee, Keun-Bae; Park, Hyeong-Won; Chung, Jae-Yoon; Moon, Eun-Sun; Jung, Sung-Taek; Seon, Jong-Keun (2010). Comparison of the Outcomes of Distraction Osteogenesis for First and Fourth Brachymetatarsia. The Journal of Bone & Joint Surgery, 92: 2709-2718.
Scientific Literature Review
Reviewed by: Kristin J. Brown
Residency Program: SCPM/Southern Arizona Veterans Affairs Hospital Clerk
Podiatric Relevance:
While most brachymetatarsia deformities do not cause pain, many patients are interested in surgical correction for aesthetic purposes. This article demonstrates that the utilization of distraction osteogenesis provides excellent outcomes with mostly minor complications for the surgical correction of congenital brachymetatarsia in the first and fourth metatarsals in adults as well as children.
Methods:
A retrospective review was undertaken in forty eight patients from 1998 to 2006, all of whom had congenital brachymetarsia in the first or fourth metatarsals that was treated via distraction osteogenesis. Patients were split into two groups, one for first metatarsal involvement, and another with fourth metatarsal involvement, both of which contained one male subject and the rest female. The average age was 20 years old and 18 years old for the first and fourth metatarsal groups respectively. All surgeries were performed by the same surgeon with the same method utilizing mini-Schanz half pins inserted into the metaphyses of the affected metatarsals, and distraction via unilateral external fixators (Dyna-EXTOR; BK Meditech). Distraction was applied at a rate of 0.25 mm three times per day, beginning one week post-op. Patients were allowed full weight-bearing beginning the second day post-op. Evaluation of the results of the procedures was done via bi-weekly x-ray evaluation and clinical assessment performed by independent blinded evaluators.
Results:
The mean length gained in the first and fourth metatarsals from this method was 17.2 mm and 16.3 mm, and with a healing index of 71.0 days/cm and 67.3 days/cm respectively. All patients reported satisfaction with the final length gained, and all demonstrated boney union radiographically. The results were analyzed statistically, and both groups showed marked improvement on AOFAS score of the metatarsophalangeal (MTPJ)-interphalangeal joints, which was statistically significant (p value < .05). Decreased MTPJ dorsiflexion was noted postoperatively, which also showed significance. There were twenty six complications reported in each group, 19 major (including hallux valgus, cavus deformity, and varus angulation), and 33 minor (MTPJ stiffness or subluxation, pin breakage, and pin-track infection). Of the minor complications, MTPJ stiffness or subluxation was most common, making up 25 of the cases. Children were shown to have a shorter healing index as compared to adults, which showed significance.
Conclusions:
The surgical treatment of brachymetatarsia is undertaken with the goal of restoring a functional metatarsal parabola and cosmesis. Outcomes in healing time and length gained were comparable between the first and fourth rays, and excellent or good improvement was demonstrated clinically in a vast majority of patients. Children demonstrated even more impressive results than the adults. Complications post-operatively may be frequent, most frequently MTPJ stiffness. Overall, distraction osteogenesis was demonstrated as a viable option for the surgical correction of congenital brachymetatarsia of the first and fourth metatarsals in adults as well as children.