Histomorphometric evaluation of mechanoreceptors and free nerve endings in human lateral ankle ligaments.
BACKGROUND
Joint mechanoreceptors have been studied and most of investigators recognize the potential role of mechanoreceptors in the proprioceptive function of joint. The aim of this study was to analyze the general innervation and the possible existence of sensory receptors in the lateral ankle ligament.


METHODS
Lateral ankle ligaments including anterior talofibular, posterior talofibular and calcaneofibular were obtained from 24 ankles of 13 male cadavers with ages ranging from 18 to 65 (mean 41.6) years. Each ligament was divided into three parts according to the bony attachments (proximal, central, and distal segments). Histologically mechanoreceptors (Ruffini, Pacini and Golgi) and free nerve endings were identified, and classified. Histomorphometric determination and evaluation of the density of the area of the receptor was performed by the point-counting methods.


RESULTS
The anterior talofibular, posterior talofibular, and calcaneofibular ligaments were endowed with mechanoreceptor and free nerve endings. There was a significant prevalence of Pacini (p<0.001) compared with Ruffini and Golgi. However, there was no significant difference in the mechanoreceptors density in the different ligaments analyzed (p>0.05)


CONCLUSIONS
Innervation of the lateral ankle ligaments was confirmed in this study, suggesting that the presence of mechanoreceptors could have clinical implication as well as relevance in the proprioceptive function. Future electrophysiological studies will be required to define the role in the proprioceptive and nociceptive system of the ankle.
Moraes
Miguel R B
MR
Post-Graduate Department of Surgery, Federal University of Ceará, Faculty of Medicine, 1608, Costa Mendes Professor St., 3rd floor, Rodolfo Teófilo, Fortaleza, Brazil, 60530-140.
Cavalcante
Maria Luzete C
ML
Leite
José Alberto D
JA
Ferreira
Francisco Valdecir
FV
Castro
Antônio Juvêncio O
AJ
Santana
Mariana G
MG
D000293:Adolescent; D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000033:anatomy & histology*; D001369:Axons / Q000502:physiology; D002102:Cadaver; D006801:Humans; D008023:Ligaments, Articular / Q000294:innervation*; D008297:Male; D008465:Mechanoreceptors / Q000033:anatomy & histology*; D008875:Middle Aged; D009411:Nerve Endings / Q000033:anatomy & histology*