orthopedic paper VI
Fifth metatarsal fracture caused by varus sprain
Report of 30 cases
Abstract
This study presents a clinical analysis of 30 confirmed cases of avulsion fractures at the base of the fifth metatarsal bone caused by inward ankle sprains. The cases were collected from our hospital since 1983 and have been followed up from 1 to 8 years. All cases were between the ages of 23 and 54, predominantly affecting active middle-aged individuals. Typical recovery occurs within 1-2 months with conservative or no treatment.
Clinical Data
Among the 30 patients, 22 were male, and 8 were female. The age range was between 23 and 54 years, with 24 cases under the age of 40. All injuries occurred due to accidental inward twisting of the foot while walking. Of these, 28 cases had insignificant fracture dislocation, and 2 cases exhibited comminuted fractures. Generally, functional recovery was noted within 1 to 2 months, either with conservative treatment or without treatment.
Discussion
Aside from direct force or open wounds, fractures caused by unintentional inward twisting of the foot during regular walking activities often go unnoticed by both clinicians and patients. Diagnosis is often delayed several days until soft tissue swelling recedes but symptoms persist. The mechanism of these fractures involves abrupt excessive inversion of the foot and intense contraction of the peroneus brevis muscle, leading to an avulsion fracture at its point of attachment at the base of the fifth metatarsal. Fracture lines are often oblique, irregular, and separated. Clinically, local tenderness is prominent, often accompanied by subcutaneous bruising and prolonged swelling, which hinders normal walking and activities. An X-ray diagnosis can prevent missed cases.
For fractures where dislocation and separation are apparent, three weeks of external support with an outward plaster cast is required; otherwise, no special treatment is generally necessary. After an appropriate rest period of 2 to 3 weeks, and once symptoms have disappeared, weight-bearing walking and exercises can resume without waiting for radiographic evidence of bone healing.
In our study, 30 cases were observed over 1 to 8 years, and no case exhibited any functional impairment. This was attributed to the fact that the external force from a simple sprain was insufficient to cause severe anatomical disarray or destruction of the transverse and lateral arches of the foot.
This article was originally published in Journal of Wannan Medical College, 1994, Vol 13, Supplemental Issue Changhang Hospital, Li Mingjie
from 足内翻扭伤致第五跖骨基底部骨折30例
