Applied Anatomical Study Of The Relationship Between The Medial Calcaneal Nerve And Inferior Calcaneal Nerve And Plantar Heel Pain

Plantar heel pain(PHP) is a very common symptom among patients who seek orthopaedic care.Most of the literature on the subject has focused on the tarsal tunnel syndrome,plantar fasciitis or the role of a heel spur in such pains.Some authors have suggested that the medial calcaneal nerve(MCN) and the inferior calcaneal nerve(ICN) may be involved in such heel pain.Anatomic descriptions of the medial nerve and inferior calcaneal nerve could be found in former reports,However,the anatomic descriptions were not adequately detailed and not fully identified.Therefore,the aim of the present study is to further describe anatomical characteristics of the medial and inferior calcaneal nerve,and to investigate the relationship between them and plantar heel pain,hence to establish an anatomical guide for study,diagnosis and therapy of neurogenic plantar heel pain(NPHP).Part one Applied anatomy of medial ealeaneal nerve and its relationship with plantar heel painObjective To explore the regional anatomy of the medial calcaneal nerve and its relationship with plantar heel pain.Methods The both lower limbs of 32 formalin-embalmed adult cadavers(19 male,13 female) were used in the present study.The tibial nerve was dissected to trace the medial calcaneal nerve from the middle third of the leg down to the fat pads over the heel.The origin,course,branches and distribution of MCN were Observed.The distances of origins and branching point of MCN to a line drawn from the tip of the inferior medial maUeolus to inferior border of the insertion of the Achilles tendon were all measured with a sliding caliper(degree of accuracy 0.02mm),and the data were analyzed with statistical software SPSS11.5.Results The frequency of the MCN was 100%in 64 lower limbs.The medial calcaneal nerve which is consisted of one principal trunk arose from the tibial nerve in 56.25%(36 feet);The medial calcaneal nerve consists of two principal trunks in 31.25% (20 feet) and of three principal trunks in 12.5%(8 feet) which all originate from the tibial nerve except 23.44%(15 feet) MCN of which arose respectively from the tibial nerve and medial plantar nerve.In 46.88%(30 feet) of the dissected specimens,The origin of MCN at the proximal flexor retinaculum and runs medialis to the flexor retinaculum,perforating the flexor retinaculum,lay superficial to the abductor hallucis muscle whose superficial aponeurosis thicken and form apparent calcaneal tunnel which encase MCN in 31.25%(20 feet).The medial(principal) branch of medial calcaneal nerve are always occurrence;The anterior branch or(and) posterior branches of MCN arose either independently or from a common trunk with a medial branch.MCN runs through the vesicles which is made of the fatty and fibrous tissue of the pad of the heel innervates the superficial tissues overlying the inferior aspect of the plantar fascia.Conclusions(1) The medial calcaneal nerve is probably entrapped at the points of entering and emerging from flexor retinaculum and in calcaneal tunnel;(2) Medial calcaneal nerve compression is associated with the occurrence and pain of plantar fasciitis.Part two Applied anatomy of the inferior calcaneal nerve and its relationship with plantar heel painObjective To explore the regional anatomy of the inferior calcaneal nerve and its relationship with plantar heel pain.Methods The both lower limbs of 32 formalin-embalmed adult cadavers(19 male,13 female) were used in the present study.The inferior calcaneal nerve was exposed from the middle third of the leg down to plantar surface the heel.The origin, course,branches and distribution of ICN were observed.The distances of origins of ICN to a line drawn from the tip of the inferior medial malleolus to inferior border of the insertion of the Achilles tendon(calcaneal tendon) were all measured with a sliding caliper(degree of accuracy 0.02mm),and the data were analyzed with SPSS11.5 statistical software.Results The rate of occurrence of the inferior calcaneal nerve(ICN) was 100% in 64 lower limbs.ICN originated from the bifurcation of the TN in 31.25%,from the TN in 18.75%and from the LPN in 50%of the dissected specimens.The inferior calcaneal nerve bifurcated into the posterior and anterior branches before passing the abductor hallucis and the medial caudal margin of the medial head of the quadratus plantae.The anterior branches of ICN which run at a mean distance of(6.02±0.68)mm anterior tubercle of the calcaneus gave rise to two branches respectively to the anterior tubercle of the calcaneus innervating its periosteum and to the long plantar ligament. The mean distance between the anterior calcaneus and the posterior branches of ICN which mainly innervated the abductor digiti minimi was(9.56±2.79)mm.Conclusions The posterior and anterior branches of inferior callcaneal nerve were possible to be simultaneously(or respectively) entrapped and manifest various symptoms.2.Plantar heel pain occurs when the branch for the long plantar ligament would be more probably exposed to pressure from a calcaneal spur,but symptoms such as atrophy or abduction limitiation of abductor digiti minimi was not necessary.Part three Positional relationship between the medial calcaneal nerve and inferior calcaneal nerve and its clinical significance for diagnosis and treatment of plantar heel painObjective To investigate the positional relationship between the medial calcaneal nerve and inferior calcaneal nerve and its clinical significance for diagnosis and treatment of plantar heel pain.Methods The both lower limbs of 32 formalin-embalmed adult cadavers(19 male, 13 female) were used in our study.The medial and inferior calcaneal nerve was exposed from the middle third of the leg down to plantar surface the heel.The distances from origin of ICN to bifurcation of TN and origin of MCN were measured.The reference lines AB and AB were were established by using four palpable anatomical landmarks,the inferior border of the insertion of the Achilles tendon(point A),the inferior tip of the medial malleolus(point B),the navicular tuberosity(point C).the number of the medial and inferior calcaneal nerves were amounted;the average distances from the points at which medial and inferior calcaneal nerves transected reference lines AB,AC to point A were measured.The data were analyzed with SPSS11.5 statistical software.Results The origin of the inferior calcaneal nerve was always distal to the origin of the medial calcaneal nerve,the mean distance was(34.19±10.35)mm to the origin of the medial and(14.70±5.80)mm to the bifurcation of the tibial nerve.More than one branch of the medial calcaneal nerve transected reference lines AB,AC.But the course of the medial(principal) branches of medial calcaneal nerves which traveling through AB averaged 44.46%,through CD averaged 39.68%was relatively constant; While the inferior calcaneal nerve traveling through AB averaged 49.26%,through CD averaged 41.63%.The course of the medial(principal) branch of medial calcaneal nerve was consistent with the inferior calcaneal nerve's,MCN runs through the superficial layer of ICN or posterior part of superficial layer of ICN.On in terms of the distances of AB and AC,the male is a little bit bigger than the female,but the average points at which the medial branch of medial calcaneal nerves and inferior calcaneal nerve transected Lines A to B,A to C are no distinguished difference between male and female by Statistical Analysis.Conclusion(1) Inferior calcaneal nerve block which has less effects to other nerve branches and was easy to carry out,would distinguish that the cause of the heel pain is whether entrapment of the medial calcaneal nerve or entrapment of the inferior calcaneal nerve;(2) The course of the medial(principal) branch of medial calcaneal nerve was similar to that of the inferior calcaneal nerve;Having acquaintance with applied anatomy of the nerves was useful to avoiding injury of the callcaneal nerves during decompression of the inferior calcaneal nerve.