Fractures of the navicular can occur in isolation but, owing
to the intimate anatomical and biomechanical relationships, are
often associated with other injuries to the neighbouring bones and
joints in the foot. As a result, they can lead to long-term morbidity
and poor function. Our aim in this study was to identify patterns
of injury in a new classification system of traumatic fractures
of the navicular, with consideration being given to the commonly associated
injuries to the midfoot. We undertook a retrospective review of 285 consecutive patients
presenting over an eight- year period with a fracture of the navicular.
Five common patterns of injury were identified and classified according
to the radiological features. Type 1 fractures are dorsal avulsion
injuries related to the capsule of the talonavicular joint. Type
2 fractures are isolated avulsion injuries to the tuberosity of
the navicular. Type 3 fractures are a variant of tarsometatarsal
fracture/dislocations creating instability of the medial ray. Type
4 fractures involve the body of the navicular with no associated
injury to the lateral column and type 5 fractures occur in conjunction
with disruption of the midtarsal joint with crushing of the medial
or lateral, or both, columns of the foot.Aims
Patients and Methods
We dissected 12 fresh-frozen leg specimens to
identify the insertional footprint of each fascicle of the Achilles tendon
on the calcaneum in relation to their corresponding muscles. A further
ten embalmed specimens were examined to confirm an observation on
the retrocalcaneal bursa. The superficial part of the insertion
of the Achilles tendon is represented by fascicles from the medial
head of the gastrocnemius muscle, which is inserted over the entire
width of the inferior facet of the calcaneal tuberosity. In three
specimens this insertion was in continuity with the plantar fascia
in the form of periosteum. The deep part of the insertion of the
Achilles tendon is made of fascicles from the soleus tendon, which
insert on the medial aspect of the middle facet of the calcaneal
tuberosity, while the fascicles of the lateral head of the gastrocnemius
tendon insert on the lateral aspect of the middle facet of the calcaneal
tuberosity. A bicameral retrocalcaneal bursa was present in 15 of
the 22 examined specimens. This new observation and description of the insertional footprint
of the Achilles tendon and the retrocalcaneal bursa may allow a
better understanding of the function of each muscular part of the
gastrosoleus complex. This may have clinical relevance in the treatment
of Achilles tendinopathies. Cite this article: