Fracture Metatarsal

In children common areas of appendicular stress fracture are the tibia, fibula or metatarsals and... 

Accessory ossification centres may occur in the epiphyses of the metatarsals and phalanges of the toes. They are particularly common in the great toes (Fig. 7.50). Incompletely fused metatarsal pseudoepiphyses can be mistaken for fractures. These occur distally in the first metatarsal and proximally in the... 

With knowledge of common accidental fractures, the finding of a fracture at an unusual site will suggest an unusual mechanism of injury. In the absence of a history of an unusual mechanism, abuse should be considered. Unusual sites of fractures in infants and toddlers include phalanges (Fig. 11.9), meta-carpals, metatarsals, pelvis and scapula (Fig. 11.10). Pelvic fractures have been described in association with sexual abuse (Johnson et al. 2004). 

Fig. 11.9. Phalangeal and metatarsal fractures. The bases of the 3" and 4 metatarsals show increased density because of internal callus formation...

Metatarsal Fractures 245 Base of 5 Metatarsal Fractures 246 Stress Fractures 247... 

Accessory centres are commonly seen in the foot 50 have been described (Hoerr et al. 1962) but only 20 are common. An accessory navicular, os tibiale externum, is seen on the medial or internal aspect of the navicular in 10% of children, usually after the age of 5 and more often in girls (Drennan 1992). Another variant, the os intermetatarsale, commonly situated between the bases of the first and second metatarsals can be misdiagnosed as a foreign body. Accessory ossicles can be readily distinguished from fractures by their consistent anatomical location and smooth well corticated margins. 

AP, true lateral and oblique radiographs are required. Occasionally these injuries reduce spontaneously leaving little radiographic evidence. Fractures near the base of metatarsals should raise suspicion and prompt closer examination. The base of second metatarsal is fractured in 75% of Lisfranc injuries (VouRi and Aro 1993 Wiley 1981). A fracture of the second metatarsal with a cuboid fracture is strongly indicative. On the AP and oblique radiographs a Lisfranc fracture dislocation can be diagnosed by loss... 

Overall, the fifth metatarsal is the most frequently injured but patterns are age dependent. Children under 5 years age have a higher proportion of first metatarsal fractures (Owen et al. 1995). A buckle fracture of the first metatarsal in young children is commonly known as the bunk bed fracture because of its frequent occurrence in children who have sustained a fall from an upper bunk (Oesterich and Crawford 1985). 

Freiberg s disease is avascular necrosis of a metatarsal head, usually the second. This should not be confused with an acute fracture. Flattening of the head and altered density help to differentiate the two (Fig. 16.8). 

Fig. 16.6. a Divergent Lisfranc injury with loss of alignment of medial border of second metatarsal and medial border of medial cuneiform, b Convergent Lisfranc. Note fracture fragments from second metatarsal base. (Images provided by Dr. Davies and Dr. Teh)... 

These fractures are typically subdivided into three types depending on their location. Zone 1 is the cancellous tuberosity, which includes the insertion of the peroneus brevis and abductor digiti minimi tendons and the lateral cord of the plantar fascia. Zone 2 is the distal aspect of the tuberosity and includes dorsal and plantar ligamentous attachments to the fourth metatarsal. Zone 3 comprises the zone distal to the ligamentous attachments to the mid-diaphyseal area. 

The apophyses maybe mistaken for a Zone 1 fracture by the unwary. The ossification centre appears between the ages of 6 and 15 years. It can simulate a fracture but its orientation is parallel to the shaft of the fifth metatarsal unlike fracture lines which are perpendicular (Fig. 16.9). 

There are typically two sesamoids located on the plantar aspect of the head of the first metatarsal. The medial sesamoid is usually larger than the lateral. On occasion it can he bipartite and should not be mistaken for fracture. 

Fig. 16.9. a A normal secondary ossification centre at the base of fifth metatarsal the apophyses runs parallel to the shaft of the bone, b Fracture at the base of fifth metatarsal, c A fracture and secondary ossification centre... 

Inokuchi S, Usami N, Hiraishi E, Hashimoto T (1998) Calcaneal fractures in children. J Pediatr Orthop 18 469-474 Jones R (1902) Fracture of the base of the fifth metatarsal by indirect violence. Ann Surg 35 697-700 Kay RM, Tang CW (2001) Pediatric foot fractures evaluation and treatment. J Am Acad Orthop Surg. 9 308-319 Logan B, Singh D, Hutchings R (2004) McMinn s colour atlas of foot and ankle anatomy, 3rd edn. Mosby, Elsevier Mora S, Thordarson DB, Zionts CE, Reynolds RA (2001) Pediatric calcaneal fractures. Foot Ankle Int 22 471-477... 

Levodopa intake is associated with increased homocysteinemia that is known to be linked to poorer bone quality and, consequently, osteoporotic fractures. The following is a case of a young woman who suffered recurrent metatarsal fractures in the context of levodopa-treated early-onset Parkinson s disease [70 ]. 

A 46-year-old woman experienced the first symptoms of Parkinson s disease, which were treated with ropinirole and levodopa-carbidopa. That regimen controlled her extrapyramidal symptoms well for one year when bilateral foot choreiform dyskinesias appeared as levodopa efficacy wore off. Two years later, she consulted her family doctor for left foot pain 4 years ago. Foot radiographs showed diaphyseal fractures of the second and fifth metatarsi treated with a cast, but 5 months later, she still had left foot pain, now associated with contralateral pain. New radiographs showed aggravation of the left second metatarsal fracture and new fractures of the fourth and fifth right metatarsi and third left metatarsus. Her biopsy result showed no evidence of a secondary cause of osteoporosis. Dual-energy X-ray absorptiometry detected... 

Stress fractures result from repetitive stress forces transferred to bone they can be divided in fatigue fractures and insufficiency fractures. Fatigue fractures occur when normal bone undergoes repetitive overuse stressing distal to the fracture site. Insufficiency fractures involve weakened bones that are more vulnerable to normal stresses these fractures are observed in aged women with osteoporosis and involve, in most cases, the calcaneus and the metatarsals. On the other hand, fatigue fractures typically involve the lower extremities... 

Weinfeld SB, Haddad SL, Myerson MS (1997) Metatarsal stress fractures. Clin Sports Med 16 319-338... 

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