SLR - December 2015 - Benjamin Harkess

Title: Ray Amputation for the Treatment of Foot Macrodactyly in Children

Reference: Kim J, Park JW, Hong SW, Jeong JY, Gong HS, Baek GH. Ray Amputation for the Treatment of Foot Macrodactyly in Children. Bone Joint J. 2015 Oct; 97-B(10): 1364-9.

Scientific Literature Review

Reviewed By:  Benjamin Harkess, DPM
Residency Program:  New York Presbyterian Queens

Podiatric Relevance:
Macrodactyly is a rare congenital anomaly characterized by enlargement of the digits in the hand or foot. Primary macrodactyly is defined as congenital overgrowth of a digit that occurs in isolation without limb hypertrophy or vascular anomaly. Incidence rate is 1/18,000 people. Etiology remains known.  Macrodactyly most commonly involves the second ray, followed by the third, first, fourth, and fifth. Conservative treatment includes accommodative shoe gear. The goal of surgical treatment is to achieve reduction of foot size in order to wear regular shoe gear and improve cosmetic result.

Methods: Study design consisted of a retrospective cohort study of 18 feet in 16 patients seen from January 1998 to December of 2012 at Seoul National Hospital.  Inclusion criteria were diagnosis of macrodactyly, ray amputation surgery, and follow-up for more than two years. Exclusion criteria include patients who refused amputation or had previous surgical intervention. Mean age at time of surgery was 46 months (12 to 151). Six patients had macrodactyly of the right foot, eight on the left, and both feet were involved in two patients. Intermetatarsal width and forefoot area data were measured post-operatively and compared to the contralateral foot. Oxford Ankle Foot Questionnaire was performed pre-operatively. The same surgeon performed all operations. Ray amputation was performed using both dorsal and plantar approaches. Patients were followed at two weeks, six weeks, three months, and every six months after. Return to weight bearing at six weeks. The Oxford questionnaire was re-administered two years post-operatively.  

Results: The mean pre-operative intermetatarsal ratio was 1.31(1.09 to 1.69) which decreased to a mean of 1.07(0.94 to 1.22) six-weeks post-operatively. At two years post-operatively, the intermetatarsal ratio increased to 1.11 which was statistically significant using Wilcoxon signed-rank test. The mean forefoot area ratio was 1.57(1.22 to 2.11) pre-operatively which decreased to 1.12(0.9 to 1.43) at six-weeks post-operatively. At two years post operative, the mean area increased to 1.22(0.96 to 1.55).  The mean pre-operative QxAFQ-C score was 42(16 to 57) increasing to 47(5 to 60) at two years after surgery. At initial evaluation, 11 out of the 16 patients wore an oversized shoe on the affected side. Of these, four could wear the same size shoe as the unaffected side. Four patients who wore correctly sized shoes pre-operatively could still wear the same shoes post-operatively with no discomfort. One patient who wore custom shoes pre-operatively was able to transition to “off the shelf” shoes post-operatively with no discomfort. Ten patients had discomfort from the operative scar at the plantar aspect of the foot. Of the 16 patients, 14 were satisfied with their surgical management.  

Conclusion: Macrodactyly of the foot is a rare, congenital but not hereditary, overgrowth condition that results deformity, pain, poor function, and inability to fit into regular shoe gear. In some patients it can cause psychological and social distress as a result of the cosmetic appearance. The objective of surgical treatment of macrodactyly is to relieve pain, restore function, and allow for the same size shoe as the contralateral side. Ray amputation was successful in reducing foot size and the clinical outcomes were excellent. All patients returned to regular shoe, and 14/16 patients were satisfied with the outcome. Limitations of the study include inability to obtain weight-bearing x-rays in all patients. It should be noted that for the patient who does not have pain but requires a larger shoe size, the risk of surgery may outweigh the benefits as the plantar scar could result in discomfort.

Educational Opportunities