[New varieties of lateral metatarsophalangeal dislocations of the great toe].
OBJECTIVE
We report seven cases of traumatic dislocation of the great toe, detailing the anatomy, the mechanism of injury and the radiographic diagnosis. We propose an additional classification based on three hereto unreported cases.


METHODS
Between october 1994 and october 1997, we treated seven patients with traumatic dislocation of the first metatarso-phalangeal joint of the great toe. There were six men and one woman, mean age 35 years (range 24 - 44 years). Dislocation was caused by motor vehicle accidents in four cases and by falls in three. Diagnosis was made on anteroposterior, lateral and medial oblique radiographs. According to Jahss' classification, there was one type I and three type IIB dislocations. There was also one open lateral dislocation and two dorsomedial dislocations. Only these dorsomedial dislocations required open reduction, done via a dorsal approach. Mean follow-up was 17.5 months (range 9 - 24 months) in six cases. One patient was lost to follow-up. The outcome was good in six cases and poor in one (dorsomedial dislocation).


CONCLUSIONS
Dislocation of the first metatarso-phalangeal joint of the great toe is an uncommon injury. In 1980, Jahss reported two cases and reviewed three others described in the literature. He proposed three types of dislocation based on the feasibility of closed reduction (type I, II and IIB). In 1991, Copeland and Kanat reported a unique case in which there was an association of IIA and IIB lesions. They proposed an addition to the classification (type IIC). In 1994, Garcia Mata et al. reported another case which had not been described by Jahss and proposed another addition. All dislocations reported to date have been sagittal dislocations. Pathological alteration of the collateral ligaments has not been previously reported. In our experience, we have seen one case of open lateral dislocation due, at surgical exploration, to medial ligament rupture and two cases of dorsomedial dislocation due, at surgical exploration, to lateral ligament rupture.


CONCLUSIONS
We propose another additional classification with pure lateral dislocation (type III) and dorso-lateral dislocation (type IL or IIL+), which are related to the formerly described variants.
Bousselmame
N
N
Service d'Orthopédie-Traumatologie (Pr. I. Moulay), Hôpital Militaire d'Instruction Mohamed V, Rabat, Maroc.
Rachid
K
K
Lazrak
K
K
Galuia
F
F
Taobane
H
H
Moulay
I
I
D000058:Accidental Falls; D000063:Accidents, Traffic; D000328:Adult; D001359:Aviation; D001696:Biomechanical Phenomena; D005260:Female; D005592:Fracture Fixation / Q000379:methods; D050723:Fractures, Bone / Q000145:classification* / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D006214:Hallux / Q000293:injuries*; D006801:Humans; D015601:Injury Severity Score; D004204:Joint Dislocations / Q000145:classification* / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D008023:Ligaments, Articular / Q000293:injuries; D008297:Male; D008683:Metatarsophalangeal Joint / Q000293:injuries*; D011859:Radiography; D012421:Rupture; D016896:Treatment Outcome