Frequency of Agenesis Palmaris Longus through Clinical Examination - An East African Study

Abstract

IntroductionThe Palmaris longus, one of the most variable muscles in the body both flexes the wrist and tenses the palmar fascia. It is used by surgeons as a source of tendon graft and racial differences in its variation have been documented. We sought to determine the frequency of the absence of the Palmaris longus in an East African population.MethodsA prospective study was conducted using ten common clinical tests among patients and students in a large teaching hospital in East Africa to determine the presence of a Palmaris longus.ResultsThe overall rate of absence was 4.4% with unilateral absence at 3.3% and bilateral absence at 1.1%. The overall difference between males and females was not statistically significant (p = 0.605). Participants were more likely to have absence in their non dominant hand.DiscussionOur findings though in contrast to many studies worldwide, it concurs with most studies done in the African setting. These differences may be due to the higher levels of manual labour and the more use of the right hand in these activities. The frequency of the absence of Palmaris longus in East Africa has been determined. Surgeons should acquaint themselves with prevalence in their areas of practice.

The sonographic morphology of musculus palmaris longus in humans

“…Despite its potential unreliability, Shaeffer's test is still vastly used both in clinic and in the research, even by authors who criticize it in their publications, mostly due to its simplicity [9,11,12,17,20]. In some situations, to avoid the above mentioned unreliability, authors tend to complement Shaeffer's test with other clinical tests such as Pushpakumar's, Mishra's, Thompson's or Gangata [1,9,11,12,20], however in most cases the differences between tests are marginal changes in fingers positioning or pressure applying [17].…”

“…In some situations, to avoid the above mentioned unreliability, authors tend to complement Shaeffer's test with other clinical tests such as Pushpakumar's, Mishra's, Thompson's or Gangata [1,9,11,12,20], however in most cases the differences between tests are marginal changes in fingers positioning or pressure applying [17]. It seems reasonable to question such methods as potentially susceptible to human error.…”

“…Other researchers, focused on relations between humans and different types of primates, argue that those relations would also suggest a recessive set of genes [19]. One of the theories used to explaining much less common agenesis in African population compared to Euro-Asian groups draws correlation between prevalence of PL and type of labor performed most commonly by specific ethnic groups throughout the ages, specifically manual labor in Africa [12]. Undoubtedly, anthropological studies need to be backed by local history research as proven by experiment in Dercen -an isolated Ukrainian village of Hungarian origin, which revealed unusual pattern -among people born before 1945 over 70% showed PL agenesis with over 50% being bilateral absence.…”

“…Most authors seems to agree that PL agenesis frequency depends on ethnicity of the test subjects and that unilateral absence is about twice as often as bilateral absence [11,12,20,21]. This study, performed on young adults from various sites of Poland, does not fall into described model, nor it follows the frequency of agenesis characteristic for Polish population (being 15% instead of expected 8,6%), falling closer to Jewish (19,5%) or generalized European-Caucasian (15,2%) [11].…”

“…Due to that, and due to being fully developed at birth unlike other potential options, PL is commonly used in tendon grafts, lip and chin restorations, ptosis corrections, eyelid defect and facial paralysis treatment as well as other plastic surgery procedures. It is also used as an important landmark, and for genetic and anthropological studies [1,9,12,20]. Attachment of the PL to the aponeurosis palmaris may improve tension of the aponeurosis which is necessary for adequate grasp of the hand and fingers (Fig.…”