Prevalence of little finger brachymesophalangia (BMP-V) in the Chinese population

Abstract

This study aims at determining the prevalence of little finger brachymesophalangia (BMP-V) in the Chinese ethnic population. A retrospective study reviewing hand radiographs taken in United Christian Hospital from January 2011 to July 2016. Exclusion criteria included previous hand trauma, background history of genetic syndromes and non-Chinese ethnic origin. The radiographs were assessed with objective measurement using computer software and were defined BMP-V with the following criteria: (1) 5th MP length: 4th MP length <0.65 and (2) 5th MP length: 5th PP length <0.50. The radiographs would be included as BMP-V cases if they fulfil both criteria. A total of 563 hand radiographs in 394 patients (290 left hands and 273 right hands; 169 bilateral hands) were reviewed. The mean age (± standard deviation) was 51.3 ± 11.7 years (ranging from 25 to 69 years). Forty-four patients were identified to have BMP-V. The prevalence of BMP-V was found to be 11.2%. Clinodactyly with trapezoidal shape middle phalanx was found in 6.82% of the BMP-V cases. All subjects with bilateral hand radiographs showed symmetrical findings concerning the presence of BMP-V. This is the first study to report the prevalence of brachymesophalangia-V in the Chinese adult population. The prevalence of BMP-V in the Chinese adult population was found to be 11.2%. It is lower than Japanese group but higher than other ethnic groups documented in other studies.