Role of Shortened Proximal Phalanx

The shortened proximal phalanx in brachymetatarsia is 5mm shorter and influences the shortened clinical appearance of the toe, a new study suggests.
Brachymetatarsia is a congenital deformity in which a metatarsal bone does not grow out to full length. It is caused by premature physeal closure. The researchers wanted to determine the length of the proximal phalanx in a patient with brachymetatarsia, and how much the shortening is attributed to the smaller toe.
The study was published on June 11, 2022, in the Journal of Foot & Ankle Surgery. (The Role of the Shortened Proximal Phalanx in the Setting of Brachymetatarsia - The Journal of Foot and Ankle Surgery (jfas.org))
The researchers conducted a retrospective study to evaluate the length of the proximal phalanx in the shortened ray. Overall, 97 feet with congenital brachymetatarsia were included in the study. The 66 patients underwent surgery to bring the metatarsal to the desired length of correction between January 2005 and February 2020 all at the same institution.
The majority of the patients were female with a mean age of 27.5 years. The researchers found that the average length of the proximal phalanx associated with the affected metatarsal was 18.9 ± 3.83mm for males and 15.6 ± 4.02 for females.
“Our results indicate the shortened proximal phalanx is 5mm shorter when compared to normal population and is a contributing factor to the shortened clinical appearance of the digit in brachymetatarsia. Treating surgeons should be aware of this to better educate patients on the influence of the digit on the overall shortening seen in cases of brachymetatarsia,” the researchers wrote.
Noman Siddiqui, M.D. of Sinai Hospital of Baltimore told OTW, “The primary reason for the shortened clinical appearance of the toe is the corresponding metatarsal bone is short. This will result in contracted soft tissue of the digit. The combination of bony and soft tissue malformation results in the overall appearance being shorter in the presence of normal adjacent digits.”
The study authors included Michael A. Thomas, DPM, MS AACFAS, Noman A. Siddiqui, DPM, MHA, FACFAS, Kelsey J. Millonig, DPM, MPH, AACFAS, Yumna Siddiqui, DPM, Cassandre Charles, DPM, and Bilal M. Khan, DPM, all of the International Center for Limb Lengthening, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore.